Wideband sequential feeding network for Ku-band dual circularly polarized 4 x 4 antenna array

In this article the analysis and design of a dual circularly polarized 4 x 4 antenna array operating in Ku band are discussed with emphasis on its sequential feeding network. The proposed antenna element is composed of stacked circular patches fed by a branch line coupler to introduce dual circular polarization. These antenna elements are arranged into 2 x 2 sequential fed antenna arrays with two separate sequential feeding networks for LH and RH circular polarizations. These 2 x 2 sequential fed antenna arrays are arranged to compose the proposed 4 x 4 antenna array. The proposed feeding network is implements on a single layer. Due to the coupling between the lines of the complete feeding network, matching and axial ratio of the complete antenna are degraded. Matching stubs at appropriate points on the complete feeding network are used to adjust the total performance of the designed 4 x 4 antenna array. Simulation results by using both HFSS and CST are presented for comparison. In addition, experimental verifications are presented.